Democracy Action is welcoming New Zealand First's commitment to hold a binding referendum on parliament's four Māori seats.
The pro-democracy lobby group says the Māori seats are from a bygone era, and should have been removed when MMP was introduced in 1996.
"New Zealanders' civil and democratic rights should not be based on race or ethnicity," says the group's spokesperson Lee Short.
"The National Party's policy is to abolish the Māori seats, and this policy, to put it to the people, is even better."
NZ First leader Winston Peters on Sunday announced the party would hold a binding referendum on whether to retain or abolish Māori seats if it governs after the September election.
A second referendum question will ask whether or not the size of parliament should be reduced to 100 members. The current parliament has 119 MPs.
The four Māori seats were introduced in 1867.
"Today I see a number of Māori in parliament who are the match for anyone else there. And their combination of political skills will place them in the elite in parliament," Mr Peters said.
The 72-year-old Mr Peters is of Māori descent on his father's side. He's seen as a potential kingmaker after the election, and his party has about 11 percent support in polls.
"This country is headed for a political upset," Mr Peters said.